An antiadhesive material of the present invention contains a poly-γ-glutamic acid having a weight-average molecular weight of 600,000 to 13,000,000, or a kinematic viscosity at 37°C of 2 cSt to 15 cSt when dissolved in distilled water at a concentration of 0.05 % by mass and/or a salt thereof, as an effective ingredient. The antiadhesive material of the present invention may have any form such as powder or gel form, and therefore, for example, is easy to handle even in relatively localized surgery such as endoscopic surgery and can more reliably prevent adhesion.
